Characteristic line mesh division for active earth pressure calculation in finite-element method

In order to overcome the disadvantages of human factors and less precision in mesh division,a new approach of characteristic curve mesh generation was established.Using the hypothesis of glide lines crossing at the wall-heel as a slip crack surface,the Duncan?Chang(E?υ) nonlinear elastic model was used for calculation of active earth pressure in finite-element method.The results show that constitutive model parameters play a minor role in boundary node stresses but experimental constant K and break ratio Rf have a larger impact on displacement.The maximum principal stress σ1 plays the biggest influence in stability of earth mass boundary when the internal friction angle of earth mass δ is more than 0° and it is appropriate to take σ1 as active earth pressure pa.The minimum principal stress σ3 equals pa and has an expression of Rankine's in case of δ=0°.From the distribution of pa on nodes,the total active earth pressure Ea can be decided and the corresponding position y of application point of Ea can be determined by resultant moment theorem at the bottom of earth mass.The results are compared with those from Coulomb's earth pressure theory and verified by the existing ones from experiments,indicating that the calculated precision is realizable and the new method is feasible.